1. Technical Field
The present invention relates to a liquid ejecting head and a liquid ejecting apparatus. More particularly, the present invention relates to an ink jet recording head capable of discharging a liquid ink from a plurality of nozzles.
2. Related Art
One example of a liquid ejecting head currently known in the art is an ink jet recording head that discharges ink as a plurality of ink droplets. Typically, an ink jet recording head includes a flow passage forming substrate that has pressure generating chambers which communicate with nozzles and a communicating portion which communicates with the pressure generating chambers, piezo-electric elements that are formed on one surface of the flow passage forming substrate, and a protective substrate that is bonded to one surface of the flow passage forming substrate which includes piezo-electric element holding portions for holding the piezo-electric elements. In addition, an IC, which is a driving circuit for driving the piezo-electric elements, is provided on the protective substrate. A driving circuit and the piezo-electric elements are connected to each other by connection lines composed of conductive wires through lead electrodes, which extend from one electrode of the piezo-electric using a wire bonding method.
The protective substrate protects two rows of piezo-electric elements which correspond to two rows of pressure generating chambers, with a through hole formed at the center of the protective substrate through which the connection lines pass. In the ink jet recording head disclosed in Japanese Patent Application No. JP-A-2004-148813, for example, the lead electrodes and the conductive wires are connected to each other in the through hole.
One problem with such configurations, however, is that the wire bonding method used to connect the driving circuit and the piezo-electric elements makes it difficult to reduce the size of the ink jet recording head. In addition, since the driving circuit is formed parallel to the protective substrate, the area of an actuator including the piezo-electric elements is increased.
In addition, these problems arise in other liquid ejecting heads which eject liquid materials other than ink.